1 files changed, 53 insertions, 28 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index fdbbff547106..b46b146524ce 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -160,6 +160,7 @@ struct sci_port {
 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 
 static struct sci_port sci_ports[SCI_NPORTS];
+static unsigned long sci_ports_in_use;
 static struct uart_driver sci_uart_driver;
 
 static inline struct sci_port *
@@ -2390,6 +2391,27 @@ done:
 
         uart_update_timeout(port, termios->c_cflag, baud);
 
+        /* byte size and parity */
+        switch (termios->c_cflag & CSIZE) {
+        case CS5:
+                bits = 7;
+                break;
+        case CS6:
+                bits = 8;
+                break;
+        case CS7:
+                bits = 9;
+                break;
+        default:
+                bits = 10;
+                break;
+        }
+
+        if (termios->c_cflag & CSTOPB)
+                bits++;
+        if (termios->c_cflag & PARENB)
+                bits++;
+
         if (best_clk >= 0) {
                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
                         switch (srr + 1) {
@@ -2406,8 +2428,27 @@ done:
                 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
                 serial_port_out(port, SCSMR, smr_val);
                 serial_port_out(port, SCBRR, brr);
-                if (sci_getreg(port, HSSRR)->size)
-                        serial_port_out(port, HSSRR, srr | HSCIF_SRE);
+                if (sci_getreg(port, HSSRR)->size) {
+                        unsigned int hssrr = srr | HSCIF_SRE;
+                        /* Calculate deviation from intended rate at the
+                         * center of the last stop bit in sampling clocks.
+                         */
+                        int last_stop = bits * 2 - 1;
+                        int deviation = min_err * srr * last_stop / 2 / baud;
+
+                        if (abs(deviation) >= 2) {
+                                /* At least two sampling clocks off at the
+                                 * last stop bit; we can increase the error
+                                 * margin by shifting the sampling point.
+                                 */
+                                int shift = min(-8, max(7, deviation / 2));
+
+                                hssrr |= (shift << HSCIF_SRHP_SHIFT) &
+                                         HSCIF_SRHP_MASK;
+                                hssrr |= HSCIF_SRDE;
+                        }
+                        serial_port_out(port, HSSRR, hssrr);
+                }
 
                 /* Wait one bit interval */
                 udelay((1000000 + (baud - 1)) / baud);
@@ -2474,27 +2515,6 @@ done:
          * value obtained by this formula is too small. Therefore, if the value
          * is smaller than 20ms, use 20ms as the timeout value for DMA.
          */
-        /* byte size and parity */
-        switch (termios->c_cflag & CSIZE) {
-        case CS5:
-                bits = 7;
-                break;
-        case CS6:
-                bits = 8;
-                break;
-        case CS7:
-                bits = 9;
-                break;
-        default:
-                bits = 10;
-                break;
-        }
-
-        if (termios->c_cflag & CSTOPB)
-                bits++;
-        if (termios->c_cflag & PARENB)
-                bits++;
-
         s->rx_frame = (10000 * bits) / (baud / 100);
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
         s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
@@ -2890,16 +2910,15 @@ static void serial_console_write(struct console *co, const char *s,
         unsigned long flags;
         int locked = 1;
 
-        local_irq_save(flags);
 #if defined(SUPPORT_SYSRQ)
         if (port->sysrq)
                 locked = 0;
         else
 #endif
         if (oops_in_progress)
-                locked = spin_trylock(&port->lock);
+                locked = spin_trylock_irqsave(&port->lock, flags);
         else
-                spin_lock(&port->lock);
+                spin_lock_irqsave(&port->lock, flags);
 
         /* first save SCSCR then disable interrupts, keep clock source */
         ctrl = serial_port_in(port, SCSCR);
@@ -2919,8 +2938,7 @@ static void serial_console_write(struct console *co, const char *s,
         serial_port_out(port, SCSCR, ctrl);
 
         if (locked)
-                spin_unlock(&port->lock);
-        local_irq_restore(flags);
+                spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static int serial_console_setup(struct console *co, char *options)
@@ -3026,6 +3044,7 @@ static int sci_remove(struct platform_device *dev)
 {
         struct sci_port *port = platform_get_drvdata(dev);
 
+        sci_ports_in_use &= ~BIT(port->port.line);
         uart_remove_one_port(&sci_uart_driver, &port->port);
 
         sci_cleanup_single(port);
@@ -3107,6 +3126,8 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 
         /* Get the line number from the aliases node. */
         id = of_alias_get_id(np, "serial");
+        if (id < 0 && ~sci_ports_in_use)
+                id = ffz(sci_ports_in_use);
         if (id < 0) {
                 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
                 return NULL;
@@ -3141,6 +3162,9 @@ static int sci_probe_single(struct platform_device *dev,
                 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
                 return -EINVAL;
         }
+        BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
+        if (sci_ports_in_use & BIT(index))
+                return -EBUSY;
 
         mutex_lock(&sci_uart_registration_lock);
         if (!sci_uart_driver.state) {
@@ -3239,6 +3263,7 @@ static int sci_probe(struct platform_device *dev)
         sh_bios_gdb_detach();
 #endif
 
+        sci_ports_in_use |= BIT(dev_id);
         return 0;
 }